International Research Journal of Engineering and Technology (IRJET)
e-ISSN: 2395-0056
Volume: 04 Issue: 08 | Aug -2017
p-ISSN: 2395-0072
www.irjet.net
Solar desalination of seawater using a single-basin single sloped solar still with a parabolic concentrator Deepak.S.A1, Sagar Shetty2, Soyal Kumar2 , Siddesha.K.M3 1Assistant
Professor, Dept. of Mechanical Engineering, AMC engineering college, Karnataka, India Undergraduate student, Dept. of Mechanical Engineering, AMC engineering college, Karnataka, India 3 Postgraduate student, Dept. of Mechanical Engineering, AMC engineering college, Karnataka, India ---------------------------------------------------------------------***--------------------------------------------------------------------2
Abstract – Many countries around the world have inadequate supply of drinking and usable water although around 71% of the earth’s surface is covered by water. This is because of the rapid growth of population and industries worldwide. Desalination of water is one of the economical solution for water scarcity problem especially in coastal areas where there is insufficient supply of fresh water and electricity. Conversion of the available brackish water into potable water can be accomplished in many ways such as distillation, ion exchange, desalination using membranes and solar desalination etc. Solar desalination using solar still is the compact, easy to fabricate and cost effective method of desalination of seawater. The fabrication of solar still involves the components wooden box, aluminium plate, water collector and glass cover. The working of the solar still is that when the solar radiations enter the solar still through the glass cover and reaches the aluminium plate mounted at the bottom of the still. The aluminium plate which is coated with black paint, has high thermal conductivity. Solar radiations are absorbed by the aluminium plate and it conducts heat to the salt water above the plate. After few hours, this heat becomes sufficient enough to form water vapour. Water vapour condenses on the glass cover and then gets collected in the water collector and passed into the measuring beaker through the outlet tube. It is found that the solar still with parabolic reflector is more efficient than the conventional solar stills.
growth in the demand for freshwater, both for domestic and agricultural purposes. Solar stills have the potential to provide desalinated water with minimal cost in coastal areas since it uses renewable solar energy and efficient components.
Key Words: Desalination, Solar still, brackish water, aluminium plate, parabolic reflector.
Bilal et.al [3] has conducted experimental analysis by using different absorber materials to enhance the efficiency of the single-basin solar still. A single-basin solar still with double slopes was used having an effective area of insulation of 3 m2. It was observed that by the use of absorbing materials such as black rubber mat, black ink and black dye, water production were increased by 38%,45% and 60% respectively.
1. INTRODUCTION Water is necessary for all plants, animals and humans. Water covers around 70% of the earth’s surface. About 97% of the water on earth exists as the salt water in the oceans and the remaining is the water in the form of ice contained in the frigid zones, groundwater, lakes and rivers. These sources furnish most human and animal needs. Only about 1% of fresh water is available for human use. Even this small fraction is believed to be adequate to support life and vegetation on earth. Most of the fresh water comes from the hydrological cycle, which itself is a very large-scale process of solar distillation to produce fresh water. However, rapid growth of population and industries worldwide has resulted in an exponential © 2017, IRJET
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1.1 Literature review A vast amount of research work has been carried out in the area of solar still. Author would like to list a few important works. In the fabrication of solar still, Tiwari et al.[1] studied the effect of cooling the glass cover on the performance of a single basin solar still. By passing the cold water at a constant velocity, the water collected is almost increased by two times when compared to a solar still with uncooled glass cover. Dependence of various operating parameters on the performance of the system has also been studied. Lawrence et.al. [2] have analysed a solar still by considering the effect of flow of water across the glass cover and by varying the volume of water present in the basin. It was found that, increase of water output and efficiency was 9% and 5%, respectively, when the water was flowing at 1.5 m/s.
Dr.S.Shanmugam[4] has conducted experimental study on a solar still with different energy absorbing materials like pebbles, black granite stones, and concrete stones immersed in salt water. These stones act like fins and helped in effective heat transfer. It is found that the concrete stones having low density and higher thermal conductivity when compared to other stones produced at least 0.9 liters water more than other stones.
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